Adhesive agent and use of such adhesive agent

ABSTRACT

A pressure sensitive adhesive composition suitable for application to human or animal skin comprising a conjugated diene polymer, a polyvinyl pyrrolidone polymer or a polyvinyl pyrrolidine vinylacetate copolymer, optionally one or more hydrocolloids and optionally a physically cross-linked elastomer selected from block-copolymers comprising styrene and one or more butadienes improves the rate of absorption of water and improves the integrity of the adhesive composition as well as the tack of an adhesive agent on wet skin.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a pressure sensitive adhesive compositionsuitable for application to human or animal skin, to a method forpreparing such adhesives and the use of such adhesive for thepreparation of a wound dressing or an adhesive wafer for an ostomyappliance or the use of the adhesive agent for securing of and sealingaround ostomy bandages, for securing wound dressings, for securing ofdevices for collecting urine, wound-drainage bandages, orthoses andprostheses and for protecting skin areas and parts of the body againstpressure, impacts and friction. Furthermore, the invention relates toostomy appliances and wound dressings comprising such adhesivecomposition.

2. Description of the Related Art

Various skin adhesive agents are used today for the above mentionedpurposes.

A very widespread embodiment of skin adhesive agents comprises aself-adhesive elastomeric matrix, in which water-absorbing, swellingparticles, the so-called hydrocolloids, are dispersed.

Adhesive compositions comprising hydrocolloids have been known for manyyears. U.S. Pat. No. 3,339,549 discloses a blend of a rubbery elastomersuch as polyisobutylene and one or more water soluble or water swellablehydrocolloids such as a powdery mixture of pectin, gelatine andcarboxymethylcellulose. The adhesive mass has a water-insoluble filmapplied to one surface. A composition of this type is availablecommercially from E. R. Squibb & Sons Inc. under the trademark“Stomahesive” and is used as a skin barrier around stomas to preventskin breakdown by the corrosive fluids discharged by the stoma.

In adhesive compositions of this type, the polyisobutylene isresponsible for provision of the adhesive properties and the dispersedhydrocolloid powders absorb fluid and render the adhesive agent capableof also adhering to moist skin (wet tack). These compositions are alsogaining increasing acceptance as wound dressings for dermal ulcers,burns and other exuding wounds.

One major problem which has been encountered with conventional adhesivecompositions comprising hydrocolloids is their susceptibility tobreakdown upon exposure to body fluids. When the compositions are usedas skin barriers, e.g., around stomas, absorption of fluid is desirable,but excessive swelling causes the composition to lose its integrityopening for leaks and the barrier must be replaced more often than isdesirable from a skin protection point of view, and very often, aresidue remains on the skin, which in many cases is difficulty toremove.

Another major problem for conventional adhesive compositions comprisinghydrocolloids is their limited capability in adhering to moist bodysurfaces. There is particularly a need for an improved adhesivecomposition having an enhanced adhesion to moist skin in the managementof ostomy patients, as it is often difficult to keep the skin aroundstomas completely dry during replacement of an ostomy appliance.

When bandaging wounds, contact with the wound exudate will in a similarway effect a disintegration of the adhesive agent which means that whenthe bandage is changed remnants will be left in the wound, whichremnants may affect the wound-healing process. Besides during use,leakage may arise which partly means reduced time of use, and partly mayincrease the risk of contaminating the wound with bacteria or othermicroorganisms.

Adhesive agents are also used for securing devices, such as uridomas,for collecting the urine from incontinent men. Disintegration of theadhesive agent due to contact with urine will again mean a risk ofleakage and a reduction of the time of use.

Adhesive agents are also employed for securing orthoses and prostheses(e.g., breast prostheses) and for protection of skin areas or parts ofthe body against pressure, impact and friction. In these cases it isprimarily the secretion of sweat which may cause swelling anddisintegration of the adhesive agent. When removing the adhesive agentremnants will be left on the skin, involving the inconveniences earliermentioned.

A number of attempts have been made to improve the integrity of adhesivecompositions.

As a method for improving the adhesive integrity, the use ofhydrocolloids has been described which, in themselves, are cross-linked(e.g., cross-linked carboxymethylcellulose (CMC), cross-linked dextraneand other water-absorbing, but insoluble hydrocolloids). They will notdissolve due to the cross-linked structure. During the swelling processthe individual particles will, therefore, obtain a gel-like structure,but no coherent gel could be formed since the macromolecules of thecross-linked hydrocolloids are locked in the gel network constituted bythe individual particles. Due to the lack of a coherent gel, thecross-linked hydrocolloids will be leached out and suspended in the bodyfluids and the effect on the integrity of the swelled adhesive,therefore, is limited.

Alternatively, as described below, it has been tried to increase theintegrity of the swelled adhesive agent by increasing the cohesion ofthe elastomeric phase. The elastomeric phase, therefore, will not soeasily be split by the expanding hydrocolloids during the swellingprocess. This process, however, has a number of drawbacks:

The rate of water absorption and thus the “wet tack” of the adhesiveagent will be reduced.

By strengthening the cohesion the elastomeric matrix will have strongerelastic properties. When the hydrocolloids absorb water and swell, thiswill enhance an increase in the dimensions of the adhesive agent. Due tothe elastic properties of the matrix, the tensions occurring in theadhesive agent cannot be relaxed by plastic deformation. Instead pleatsmay occur in the adhesive agent around the swelled area. In these pleatsthe adhesive agent will loose contact with the skin exposed to the bodyfluids, and a risk of leakage arises.

U.S. Pat. Nos. 4,192,785 and 4,551,490 describe incorporating into anadhesive composition a cohesive strengthening agent such as a natural orsynthetic fibrous material, finely divided cellulose, cross-linkeddextran, cross-linked carboxymethylcellulose or a starch-acrylonitrilegraft copolymer. The cohesive strengthening agent is stated to controlthe rate of hydration of the composition thereby increasing theresistance against breakdown by body fluids.

U.S. Pat. No. 4,477,325 describes incorporation of a mixture of acopolymer resin of ethylene and vinyl acetate (EVA) into the adhesivecomposition. After mixing and moulding, the composition is subjected toionising radiation to form a cross-linked polymer network of the EVA orcomprising EVA and another cross-linked resin. The cross-linked matrixis said to provide a controlled swelling.

U.S. Pat. No. 4,496,357 describes the incorporation of fumed silica intoadhesive compositions to control swelling.

EP No. 0 122 344 B1 describes incorporation of one or more natural orsynthetic polymers capable of developing elastomeric properties whenhydrated, such as gluten and long chain polymers of methyl vinylether/maleic acid, into the adhesive composition. The adhesivecomposition is stated to be resistant to erosion by moisture and bodyfluids.

EP Patent No. 0 340 945 B1 describes incorporation of some polycationichydrocolloid particles into a hydrocolloid composition. The mixture ofpolycationic, polyanionic and neutral hydrocolloids is stated to provideincreased integrity without a concomitant decrease in absorbingcapacity.

In existing adhesive agents the surface of the adhesive is consisting ofthe self-adhesive elastomeric matrix while the hydrocolloids are locatedembedded beneath the surface in the elastomeric matrix. In order to beabsorbed, the water thus needs to penetrate through the elastomericmatrix before reaching the water absorbing hydrocolloids. This retardsthe water-absorption and causes that the adhesive agent does not have animmediately adhesion to wet surfaces (wet tack).

Thus, there is still a need for an adhesive agent showing a very rapidwater absorption and retention in order to improve the wet tack.

Skin problems associated with an ostomy are different from skin problemsgenerally associated with adhesives for skin (dressings or plasters) asthe adhesives of ostomy appliances are placed permanently at the samesite during long periods of time (cronical irritation) whereas otheradhesives for skin are normally only placed at the same site for a shortperiod of time.

European Patent publication No. EP 0 017 401 A1 discloses articles ofmanufacture having adhesive properties useful for, for example,protective plasters or dressings or as rings, washers or the like insurgical appliances such as ostomy appliances comprising a plasticsmatrix comprising the product resulting from heating together one ormore polyhydric alcohols and gelatine and/or naturally occurring highmolecular weight polysaccharide gum and/or a resin which is a copolymerand a vinyl ether and an organic acid anhydride and/or its correspondingfree acid. Polyvinylpyrrolidone resin may be added as a tack modifier.

European Patent publication No. EP 0 343 807 A2 discloses absorptiveadhesive dressing with controlled hydration containing about 30-65%polyisobutylene, 10-30% polyvinylpyrrolidone, 2-20% modified starch,2-20% pectin, 0.1-10% acrylic polymer and 0-1% fibre. The dressingdisclosed in EP 0 343 807 A2 is a nonocclusive dressing providing acontrolled water evaporation from the wound area.

European Patent publication No. EP 0 063 898 discloses a microporoustape comprising a porous backing layer and a microporous adhesive layerincluding a rubbery elastomer such as polyisobutylene, one or more waterswellable hydrocolloids and other optional substances. A copolymer ofpolyvinylpyrrolidone and vinylacetate may be used as a tackifier.

European Patent publication No. EP 0 591 898 A1 discloses adhesivecompositions and wound dressings comprising an adhesive compositioncomprising a blend of a hydrophobic unsaturated aliphatic homopolymer, acompatible tackifier and at least one hydrocolloid adsorbent whichcomposition has been exposed to a dose of ionising radiation whichchemically cross-links the unsaturated aliphatic homopolymer component.

It has surprisingly been found that the use of an adhesive comprising aconjugated diene polymer and a polyvinyl pyrrolidone polymer or apolyvinyl pyrrolidone vinylacetate copolymer improves the rate ofabsorption of water and improves the tack of an adhesive agent on wetskin and the cohesion of the adhesive agent and also improves theperformance towards the action of aggressive exudates or excretions froma body without having to rely on the addition of other ingredients.Furthermore, it has surprisingly been found that the presence of anacrylic elastomer as a complementary binder is not necessary and that itis not necessary to have to rely on a chemical cross-linking andaddition of a tackifier in order to obtain an adhesive compositionshowing satisfactory properties, physical cross-linking has been foundto be sufficient.

BRIEF SUMMARY OF THE INVENTION

The invention relates to a pressure sensitive adhesive compositionsuitable for application to human or animal skin comprising a polyvinylpyrrolidone polymer or a polyvinyl pyrrolidone vinylacetate copolymer.Furthermore, the invention relates to a method for preparing suchadhesives and the use of such adhesive or the preparation of a wounddressing or a adhesive wafer for an ostomy appliance or the use of theadhesive agent for securing of and sealing around ostomy bandages, forsecuring wound dressings, for securing of devices for collecting urine,wound-drainage bandages, orthoses and prostheses and for protecting skinareas and parts of the body against pressure, impacts and friction.

DETAILED DESCRIPTION OF THE INVENTION

In a first aspect, the present invention relates to a pressure sensitiveadhesive composition suitable for application to human or animal skincomprising a polyisobutylene polymer, a polyvinyl pyrrolidone polymer ora polyvinyl pyrrolidone vinylacetate copolymer, optionally one or morehydrocolloids and optionally a physically cross-linked elastomerselected from block-copolymers comprising styrene and one or morebutadienes wherein the adhesive composition comprises 30-50% of apolyisobutylene polymer, 10-60% of a polyvinyl pyrrolidone polymer or10-30% of a polyvinyl pyrrolidone vinylacetate copolymer, 0-50% of oneor more hydrocolloids and 0-10% of a physically cross-linked elastomerselected from block-copolymers comprising styrene and one or morebutadienes

By introducing a polyvinyl pyrrolidone polymer or a polyvinylpyrrolidone vinylacetate copolymer in a self-adhesive elastomeric matrixan improved adhesion in moist environment is achieved. This is ascribedto the fact that the polyvinyl pyrrolidone polymer is present also atthe surface of the adhesive agent and thus is able to cause animmediately absorption of water. Due to the ability of the polyvinylpyrrolidone polymer to absorb water, the amount of hydrocolloids in theform of traditional hydrocolloid particles may be reduced and it is evenpossible to avoid such hydrocolloids in the adhesive of the invention.The improved cohesion of the adhesive allows for a complete removal ofthe adhesive after the period of service without leaving residues on theskin when used for securing an ostomy appliance

Polyvinylpyrrolidone (PVP) and vinylpyrrolidone/vinyl acetate copolymer(PVP/VA) provides a strong gel integrity. Compositions of the inventionexhibit greater resistance to degradation by biological fluids thancomparable adhesive compositions of the prior art. Furthermore, noresidue of the adhesives of the invention remains on the skin uponremoval of the adhesive.

PVP and PVP/VA are capable of absorbing water and proving a wet tack.Compositions of the invention therefore possess significantly enhancedadhesion on moist skin as compared to compositions of the state of theart.

Thus it has been found that it is possible to provide a pressuresensitive adhesive composition suitable for application to human oranimal skin consisting essentially of a conjugated diene polymer, apolyvinyl pyrrolidone polymer or a polyvinyl pyrrolidone vinylacetatecopolymer, optionally one or more hydrocolloids and optionally aphysically cross-linked elastomer selected from block-copolymerscomprising styrene and one or more butadienes and not having to relyupon chemical crosslinking in order to ensure a sufficient cohesion andalso not having to rely upon addition of tackifiers in order to ensure asufficient tack.

Furthermore, PVP and PVP/VA are hypo-allergenic and have for a long timebeen applied in the formulation of cosmetics and toiletries such asconditioning shampoos, setting lotions, skin-care products, etc. U.S.Pat. No. 5,320,838 describes that PVP together with poly-ethylene glycolforms a protectant for irritated skin. Similarly, JP 07265352 Adiscloses a patch agent for applying on a person having irritable skinin which PVP is also incorporated. Due to introducing of PVP and PVP/VA,compositions of the invention possess skin healing properties andprovides comforts on the skin. Less pain is experienced upon removal.

In one embodiment of the invention, the adhesive composition consistsonly of a conjugated butadiene polymer, a polyvinyl pyrrolidone polymeror a polyvinyl pyrrolidone vinylacetate copolymer and one or morehydrocolloids. It has even been proved possible to prepare an adhesivecomposition according to the invention comprising only polyisobutyleneand PVP having superior properties with respect to wet tack and rate ofabsorption of water.

Suitable hydrocolloids are naturally occurring hydrocolloids such asguar, locust bean gum (LBG), pectin, alginates, gelatine, xanthan orkaraya, semisynthetic hydrocolloids such as cellulose derivatives (e.g.,salts of carboxymethylcellulose, methylcellulose andhydroxypropylmethylcellulose), sodium starch glycolate and synthetichydrocolloids such as polyvinylalcohol or polyethylene glycol.

The conjugated butadiene polymer used in the adhesive of the inventionmay be polybutadiene or polyisoprene and is preferably polybutadiene.

The physically cross-linked elastomer selected from block-copolymerscomprising styrene and one or more butadienes may be astyrene-butadiene-styrene copolymer and is preferablystyrene-isoprene-styrene copolymer.

The adhesive compositions of the invention may optionally comprisefurther components normally used in formulation of adhesive compositionssuch as pigments such as zinc oxide or titanium dioxide.

In a second aspect, the invention relates to a method for thepreparation of a pressure sensitive adhesive composition of theinvention wherein the conjugated diene polymer and the polyvinylpyrrolidone polymer or a polyvinyl pyrrolidone vinylacetate copolymerare mixed during heating, whereafter optionally one or morehydrocolloids are admixed. When a physically cross-linked elastomerselected from block-copolymers comprising styrene and one or morebutadienes is present, a premix of this elastomer with the conjugateddiene polymer is formed before admixing with the polyvinyl pyrrolidonepolymer or a polyvinyl pyrrolidone vinylacetate copolymer.

When carrying out the method of the invention, the mixing of theconjugated diene polymer and the polyvinyl pyrrolidone polymer or apolyvinyl pyrrolidone vinylacetate copolymer is carried out attemperature of from about 25° C. to about 225° C. More preferred, themixing is carried out at a temperature of from 35° C. to about 180° C.When only mixing a conjugated diene polymer, a polyvinyl pyrrolidonepolymer or a polyvinyl pyrrolidone vinylacetate copolymer and nophysically cross-linked elastomer selected from block-copolymerscomprising styrene and one or more butadienes, the temperature of mixingis suitably from 50° C. to about 100° C. When also admixing a physicallycross-linked elastomer selected from block-copolymers comprising styreneand one or more butadienes, the temperature of mixing is suitably from120° C. to about 180° C.

The method of the invention is advantageously carried out at a reducedpressure in order to avoid extensive degradation. The mixing ispreferably carried out at a pressure of from 10 mbar to about 500 mbarand more preferably at from 20 to 100 mbar.

The resulting dough-like mass is then preferably removed from the mixerwhile hot and soft and formed into approximately 1 mm thick sheet stockmaterial by compression moulding the adhesive mass at a temperature offrom 50° C. to about 120° C., preferably approximately 90° C., and apressure of from 50-150 bars, preferably about 100 bars, between twosheets of silicone release paper. The resultant flat plate may then becut into the desired shapes.

In a further aspect, the invention relates to the use of a pressuresensitive adhesive composition of the invention for securing of andsealing around ostomy bandages, for securing wound dressings, forsecuring of devices for collecting urine, wound-drainage bandages,orthoses and prostheses or for protection skin areas and parts of thebody against pressure, impacts and friction.

In a further aspect, the invention relates to ostomy appliancescomprising a pressure sensitive adhesive composition of the invention.

Such appliances may be two-piece or one-piece appliances. In both typesof appliances, a body side member is attached to the wearer's abdomen,and optionally a receiving member or bag is attached to the body sideostomy member for receiving secretions from the ostomy in case of atwo-piece appliance. Such appliances are used in connection with surgeryfor a number of diseases in the gastro-intestinal tract where thepatient is left with an abdominal stoma such as a colostomy, anileostomy or an urostomy to collect the bodily material emerging fromsuch opening.

An ostomy appliance of the invention may have any form and be made fromany material known per se in connection with ostomy appliances. A bodyside member of such an appliance preferably comprises a substantiallywater-impervious layer or film and the adhesive according to theinvention and the adhesive surface is optionally covered in part orfully by one or more release liners or cover films to be removed beforeor during application.

In yet a further aspect, the invention relates to a wound dressing saiddressing comprising a substantially water-impervious layer or film and apressure sensitive adhesive according to the invention which dressing isoptionally covered in part or fully by one or more release liners orcover films to be removed before or during application.

The water impervious layer or film may be of any suitable material knownper se for use in the preparation of wound dressings e.g. a foam, or apolyurethane, polyethylene, polyester or polyamide film. In accordancewith the invention it has surprisingly been found that when using athinner backing layer or film than is normally used when preparingmedical dressings, an improved stretcheability and adaptability isobtained at the same time as the modulus is reduced. These propertiesare obtained using the same load of adhesive as is conventionally used,and thus, the conventional properties of the adhesive are retained asopposed to the case in which the load of adhesive was lowered giving arisk of insufficient tack and adhesive properties.

The water impervious layer or film is preferably a low-friction flexiblepolymer film reducing the risk of unwanted stress in the area of a skincrack impeding the healing of a crack on a very exposed site.

A dressing or ostomy appliance of the invention preferably has bevellededges in order to reduce the risk of “rolling-up” the edge of thedressing reducing the wear-time. A bevelling may be carried outdiscontinuously or continuously in a manner known per se, e.g., asdisclosed in EP Patent No. 0 264 299 or in U.S. Pat. No. 5,133,821.

A protective cover or release liner may for instance be siliconizedpaper. It does not need to have the same contour as the dressing, e.g.,a number of dressings may be attached to a larger sheet of protectivecover. The protective cover is not present during the use of thedressing of the invention and is therefore not an essential part of theinvention.

Furthermore an ostomy appliance or wound dressing of the invention maycomprise a “non touch” grip known per se for applying the dressing tothe skin without touching the adhesive layer. Such a non-touch grip isnot present after application of the dressing.

It is advantageous to provide an ostomy appliance or wound dressing ofthe invention with components for treatment or prophylaxis of formationof wounds and/or skin abnormalities, e.g., with emollients or an activeconstituent, e.g., retinoids for treating or preventing formation ofpsoriasis, eczema, callous skin, corns, insect bites, acne or blisters.The dressing of the invention may also contain medicaments such asbacteriostatic or bactericide compounds, e.g., iodine, iodopovidonecomplexes, chloramine, chlorohexidine, silver salts, zinc or saltsthereof, tissue-healing enhancing agents, e.g., RGD tripeptides and thelike, enzymes for cleansing of wounds, e.g., pepsin, trypsin and thelike, pain relieving agents, or agents having a cooling effect which isalso considered an aspect of the invention.

The invention is explained more in detail with reference to the belowworking examples disclosing embodiments of the invention which are to beconsidered illustrative only of principles of the invention. As allsuitable modifications and equivalents may be resorted to, the examplesare not to be considered as limiting the scope of the invention setforth in the appended claims.

Materials and Methods

PIB: Polyisobutylene available under the trademark Vistanex from ExxonChemical Co. as grade LM-MH.

PVP K-90: Polyvinylpyrrolidone available from ISP Inc. having amolecular weight of 630,000.

PVP/VA S-630: Vinylpyrrolidone/vinyl acetate copolymer available fromISP Inc. with a mole ratio of VP/VA 60/40.

Kraton D1107: Styrene-isoprene-styrene copolymer having a molecularweight of 212,000-260,000 (GPC) and a content of diblock of 15-25%.

Gelatine: Gelatine P.S.98.240.233 available from ED. Geistlich Sohne AG.

Pectin: Pectin LM 12CG Z or Pectin USP/100 from Copenhagen Pectin A/S.

CMC: Sodium carboxymethylcellulose available from Akzo under thetradename Akucell® AF2881 or from Hercules Corp. under the tradenameBlanose® 9H4XF.

A Z mixer Type LKB 025 from Herman-Linden was used.

Experimental Part

EXAMPLE 1

Preparation of an adhesive material according to the invention.

An adhesive having the following composition was prepared:

Ingredient Percent by weight PIB 40 PVP/VA S-630 15 Gelatine 15 Pectin20 CMC 10

80 grams of PIB and 30 grams of PVP/VA S-630 were mixed in a Z mixer for10 minutes at 80° C. and mixing was then continued under a vacuum of 50mbar for further 10 minutes. Then, the vacuum was released, and 30 gramsof Gelatine, 40 grams of Pectin and 20 grams of CMC were added and mixedfor 15 minutes and the mixing was continued under a vacuum of 50 mbaruntil a homogeneous dough-like mass was formed.

This dough-like mass was then removed from the mixer while hot and softand formed into approximately 1 mm thick sheet stock material bycompression moulding the adhesive mass at approximately 90° C. and 100Bars between two sheets of silicone release paper. The resultant flatplate was then cut into the desired shapes.

EXAMPLES 2-9

Following the procedure of Example 1 the adhesive compositions stated inthe below Tables were prepared:

Ingredient Example 2 Example 3 Example 4 Example 5 PIB 40 40 40 45PVP/VA S-630 15 30 20 15 Gelatine 15 10 10 Pectin pomosin 15 10 20 CMC15 30 20 10 Ingredient Example 6 Example 7 Example 8 Example 9 PIB 4042.5 37.5 45 PVP/VA S-630 20 12.5 17.5 15 Gelatine 10 15 15 10 Pectinpomosin 10 15 15 10 CMC 20 15 15 20

EXAMPLES 10-16

Following the procedure of Example 1 with the exception that thetemperature was increased to 90° C., the adhesive compositions stated inthe below Tables were prepared:

Ingredient Example 10 Example 11 Example 12 Example 13 PIB 40 40 40 40PVP K-90 10 30 60 10 Gelatine 20 15 Pectin pomosin 15 20 CMC 15 30 15Ingredient Example 14 Example 15 Example 16 PIB 40 40 40 PVP K-90 20 3015 Gelatine 10 15 Pectin pomosin 10 10 15 CMC 20 20 15

EXAMPLE 17

Preparation of an adhesive material according to the invention.

A premix powder was prepared by blending 30 grams of PVP/VA S-630, 30grams of Gelatine 30 grams of Pectin and 30 grams of CMC.

The PIB (100 grams) was added in a Z mixer at 150° C. and softened for 5minutes. To this was added 100 grams of Kraton® D1107 and the mixing wascontinued under 150° C. and 50 mbar until the blend was homogeneous. Themass was cooled to 80° C., and 168 grams of the mass was removed fromthe mixer. To this remaining mass was added the powdered premix. Themixing was continued under 80° C. and 50 mbar until a homogeneousdough-like mass was formed.

This dough-like mass was then removed from the mixer while hot and softand formed into approximately 1 mm thick sheet stock material bycompression moulding the adhesive mass at approximately 90° C. and 100bar between two sheets of silicone release paper. The resultant flatplate was then cut into the desired shapes.

EXAMPLES 18-20

Following the procedure of Example 17 the adhesive compositions statedin the below Table (also showing the composition of Example 17) wereprepared:

Ingredient Example 17 Example 18 Example 19 Example 20 PIB 32 32 32 35PVP K-90 10 12 PVP/VA S-630 15 20 Kraton D1107 8 8 8 8 Gelatine 15 1017.5 10 Pectin pomosin 15 15 10 15 CMC 15 15 22.5 20

EXAMPLE 21

Testing of adhesive compositions according to the invention.

Body side members having an adhesive wafer comprising an adhesiveaccording to the invention having the composition stated in Examples 1and 16 were prepared.

The body side members were tested on 25 healthy volunteers each andcompared with a commercial Coloplast Assura one piece appliance withrespect to flexibility, residue on the skin after removal, pain duringremoval, and resistance against erosion.

The results showed that both adhesives comprising polyvinyl pyrrolidonepolymer and a polyvinyl pyrrolidone vinylacetate copolymer,respectively, provided significant improvement with regards to theflexibility, residue on skin after removal, pain during removal, andresistance against erosion.

What is claimed is:
 1. A pressure sensitive adhesive compositionsuitable for application to human or animal skin and comprising a) from30-50% of a polyisobutylene polymer, from 10-60% of a polyvinylpyrrolidone polymer or from 10-30% of a polyvinyl pyrrolidonevinylacetate copolymer, b) a pigment selected from the group consistingof zinc oxide and titanium dioxide, c) from 0-50% of one or morehydrocolloids and d) from 0-10% of a physically cross-linked elastomerselected from the group consisting of a block-copolymer comprisingstyrene and one or more butadienes.
 2. A pressure sensitive adhesivecomposition as claimed in claim 1, wherein the physically cross-linkedelastomer is a styrene-isoprene-styrene copolymer.
 3. A wound dressingcomprising a pressure sensitive adhesive according to claim 1 and asubstantially water-impervious layer or film which dressing isoptionally covered in part or fully by one or more release liners orcover films to be removed before or during application.
 4. An ostomyappliance comprising a pressure sensitive adhesive composition accordingto claim 1, and optionally comprising a substantially water-imperviouslayer or film and the adhesive surface of which is optionally covered inpart or fully by one or more release liners or cover films to be removedbefore or during application.
 5. A method of using a pressure sensitiveadhesive composition according to claim 1 for securing of and sealingaround ostomy bandages, for securing wound dressings, for securing ofdevices for collecting urine, wound-drainage bandages, orthoses andprostheses or for protection of skin areas and parts of the body againstpressure, impacts and friction, comprising applying the composition tohuman or animal skin.
 6. A pressure sensitive adhesive composition asclaimed in claim 1 comprising 32 to 45% of polyisobutylene polymer, 10to 60% of polyvinyl pyrrolidone polymer or 15 to 30% of polyvinylpyrrolidone vinylacetate copolymer, 0 to 45% of hydrocolloid and 0 to 8%of a physically cross-linked elastomer.
 7. A pressure sensitive adhesivecomposition suitable for application to human or animal skin and whichconsists essentially of (a) polyisobutylene polymer, and a memberselected from the group consisting of (b) a polyvinyl pyrrolidonepolymer and (c) a polyvinyl pyrrolidone vinylacetate copolymer; saidcomposition comprising from 30 to 50% of (a), the amount of (b), whenpresent, being from 10 to 60%, and the amount of (c), when present,being from 10 to 30%.
 8. A pressure sensitive adhesive composition ofclaim 7 which further comprises a member selected from the groupconsisting of (d) a hydrocolloid and (e) a physically cross-linkedelastomer which is a block-copolymer of styrene and a butadiene; saidcomposition comprising from 0 to 50% of (d) and from 0 to 10% of (e). 9.A method which comprises applying a pressure sensitive adhesivecomposition of claim 7 to human or animal skin to secure thereto or sealaround an ostomy bandage, to secure thereto a wound dressing, to securethereto a device for collecting urine, a wound-drainage bandage, adevice for orthosis, a prosthesis or a device for protecting a skin areaor body part against pressure, impact or friction.
 10. A wound dressingcomprising a pressure sensitive adhesive according to claim 7 and asubstantially water-impervious layer or film, which dressing isoptionally covered in part or fully by one or more release liners orcover films to be removed before or during application.
 11. An ostomyappliance comprising a pressure sensitive adhesive composition accordingto claim 7, and optionally comprising a substantially water-imperviouslayer or film and the adhesive surface of which is optionally covered inpart or fully by one or more removable release liners or cover films.12. A pressure sensitive adhesive composition as claimed in claim 7comprising from 32 to 45% of polyisobutylene polymer, from 10 to 60% ofpolyvinyl pyrrolidone polymer, from 15 to 30% of polyvinyl pyrrolidonevinylacetate copolymer, from 0 to 45% of hydrocolloid and from 0 to 8%of a physically cross-linked elastomer.
 13. A pressure sensitiveadhesive composition as claimed in claim 8, wherein the physicallycross-linked elastomer is a styrene-isoprene-styrene copolymer.